Commissioned by Gian Giacomo’s mother, Rosina Trivulzio, this portrait welcomes visitors in the entrance of the house-museum. In this official image, the young Poldi Pezzoli has been painted in an interior lacking any spatial features: the dark background wall is animated only by reflections of light from the left. Depicted seated with legs crossed in a three-quarter, elegant and self-assured pose, the sitter looks intently towards the spectator, establishing an intimate and direct relationship with him.

In the past the painting was dated to about 1846-1848, due to the style of the clothes, which would have been unfashionable by 1850. Today, however, a date of 1851 is preferred, the year in which the painting was exhibited at the Brera Academy. The future founder of the Museum, having reached majority and come into possession of the family fortune, had obviously chosen to appear in dark, elegant and serious garments suitable to an official portrait.

During the mid nineteenth century Francesco Hayez was the preferred portrait painter of the Milanese upper and aristocratic classes, who loved his stringent, inner-looking painting style attentive to the psychological nature of the sitter.